The present invention relates to a pulse type activating system for power supply, in which a CPU collectively controls respective circuits and provides intermittent high voltage for shortening the activation time of the load. The pulse type activation system is especially applicable to those heavy tools necessitating great current and great voltage.
When activating a general electric appliance, the instantaneous activating current is very great. With 100 watt electric appliance exemplified, the instantaneous activating current is over 2-3 times higher than the original current. The instantaneous great current is extremely apt to damage the circuit of the electric appliance itself. A general DC-to-AC power supply is unable to provide sufficient high surge so that the ability in activating the electric appliance is affected. FIG. 1 shows a current versus time (A-T) curvature of a conventional power supply. It can be known from the diagram that for making the current reach the high surge point, a time period Tx is cost. During Tx, the load is repeatedly activated. After the load is warmed up, the amount of the activation current is time by time accumulated until the activation current is able to activate the load. Furthermore, when the activation current is close to the high surge point, sometimes the load will misjudge and shut down due to overload.
It is therefore a primary object of the present invention to provide a pulse type activating system for power supply, in which a CPU collectively controls respective circuits.
It is a further object of the present invention to provide the above pulse type activating system for power supply, which is able to quickly activate a load.
It is still a further object of the present invention to provide the above pulse type activating system for power supply, which is able to protect the circuit of the load.
According to the above objects, the pulse type activating system for power supply of the present invention is composed of a boosting circuit, a pulse width modulating (PWM) circuit, a sine-wave generating circuit, an MOSFET output circuit, an analog-to-digital converting circuit (ADC), a temperature sensing circuit, an overload detecting circuit, a short circuit detecting circuit, a warning circuit and a CPU. The boosting circuit is connected with the pulse width modulating (PWM) circuit. The output end of the boosting circuit is connected with the MOSFET output circuit. The sine-wave generating circuit is connected with the MOSFET output circuit. The MOSFET output circuit is connected with both the overload detecting circuit and the short circuit detecting circuit. The CPU is connected with the pulse width modulating (PWM) circuit, the sine-wave generating circuit, the temperature sensing circuit, the overload detecting circuit, the short circuit detecting circuit, the analog-to-digital converting circuit (ADC) and the warning circuit. The CPU collectively controls the above circuits and in the instant of activation of the load, the CPU provides intermittent high voltage for shortening the activation time of the load. The CPU also provides protection effect for the load.